A diesel electric locomotive typically has an engine that operates a shaft to drive other components for powering the locomotive. The other components can include a traction generator and an auxiliary generator.
The auxiliary generator provides power for an auxiliary load(s), and the traction generator provides power for a traction load(s). The traction load is typically associated with a different voltage level than the auxiliary load. For example, the traction generator can operate at a relatively higher voltage in comparison with an operating voltage of the auxiliary generator. As a result, at least two DC-buses may be needed.
When the auxiliary generator is provided as an AC machine, a DC/AC inverter and one of a cycle skipper and an AC/DC rectifier may need to be included. When the traction generator is provided as an AC machine, an AC/DC rectifier and a DC/AC inverter may need to be included. Brushes and slip rings are also needed when the traction generator and the auxiliary generator are provided as AC synchronous machines.